The rise of VoIP has led to widespread use of softswitch solutions to serve as the intermediary in a telecom network comprising of standard PSTN and VoIP networks. Softswitches also serve to separate call functions from the transport layer. A softswitch can also function as a VoIP server and incorporate IP PBX call features. Softswitches are classified according to the functions they perform in the VoIP network.
Typically, telecom carriers and VoIP services make use of two different kinds of VoIP softswitches. One is class 4 softswitch and the other is class 5 softswitch. Class 5 softswitch works at the retail end of the VoIP network by connecting to the end user. Class 4 softswitch addresses the need of international bulk VoIP traffic from one telecom carrier to another.
Even in class 4 softswitch segment one can find two types of such switches. One is the local tandem switch or sector. This type of class 4 softswitch usually connects to class 5 softswitch to route traffic to local areas. Traffic from an exchange in one city originates in class 5 and tries to access a number in another city and, when it cannot, the class 4 tandem switch comes into play in the other city that, in turn, connects to the local class 5 softswitch and finds the number.
The other type of class 4 softswitch is the access tandem switch. This operates between bulk telecom carriers known as interexchange carriers. The local class 4 call travels across international networks to another telecom operator in another country and accesses the class 4 softswitch in that exchange. Class 4 softswitches can be configures to suit Competitive Local Exchange Carriers (CLECs), ITSPs, Incumbent Local Exchange Carriers (ILECs) and Multi-tenant environments in addition to bulk carriers.
Softswitches have changed the way telecom carriers operate. Open source based softswitches are software solutions and are highly affordable as well as scalable. There is no need to invest in hardware as traffic goes up. Softswitches do not just route calls; they also have other features such as billing and reporting. Then there are other features such as Do Not Disturb, call hold, call back, voice and video telephony, directory, voicemail, fax to mail, call blocking, call rejection, DID, extension dialing and intelligent call routing. Softswitches can route calls through predefined instructions and thereby lower cost of international calls. At the same time, the reporting and analytics as well as monitoring functions ensure that there is no call fraud and that no calls remain unbilled, thereby increasing revenues for carriers. Businesses that switch to VoIP enjoy benefits like cost reduction of calls and increased productivity besides other features like the ability to use services on IP PBX in house and on mobiles, a boon for mobile employees.